The invention relates to directional boring machines, and more particularly to a directional boring attachment for boring through the earth in order to lay utility lines, such as gas lines, electrical conduit, communications conduit, sewer lines, and water lines.
Utility lines for water, electricity, gas, telephone and cable television are often run underground for reasons of safety and aesthetics. In many situations, the underground utility pipes, cables, and lines (collectively, xe2x80x9cutility linesxe2x80x9d) can be buried in an open trench. After the utility lines are buried, the trench is then back-filled to bring it up to grade. Although useful in areas of new construction, the burial of utility lines in an open trench in already developed areas has certain disadvantages. In previously, partially, or fully developed areas, the digging and existence of a trench can cause serious disturbance to structures or roadways. Further, digging a trench in previously developed areas creates a high risk of damaging previously buried utility lines. Another problem with digging an open trench is that structures or roadways disturbed by such digging are rarely restored to their original condition. Furthermore, a trench poses a danger of injury caused by workers or other persons inadvertently falling into the trench, or the collapse of the trench upon people working in the trench.
The general technique of boring a horizontal underground tunnel in which utility lines are placed has recently been developed in order to overcome the disadvantages described above, as well as others associated with conventional trenching techniques. Conventional directional boring machines typically include an elongated boom having a drill head that moves longitudinally forward and rearward over the length of the boom. The boom is angled relative to the surface (usually the ground) to be drilled at an angle ranging from 5xc2x0 to 25xc2x0. The drill head includes a rotating spindle, generally driven by a hydraulic motor, to which one or more elongated drill stems (also referred to as xe2x80x9ccasingsxe2x80x9d) are detachably connected.
Conventional directional boring machines operate by connecting the proximal end of a first drill stem to the rotating spindle of the drill head and connecting a drill bit to the opposite or outer (distal) end. With the drill head in a retracted position on the boom, spindle rotation begins and the drill head is advanced axially and distally down the boom resulting in the drilling of a bore. When the drill head reaches the outer (distal) boom end, the proximal end of the drill stem is detached from the drill head spindle and the drill head is retracted to its original position. The proximal end of a second drill stem is then mounted to the spindle with the distal end of the drill stem being connected to the proximal end of the existing first drill stem. The drilling process then continues until the drill head again reaches the distal end of the boom, and the process is repeated.
The drill stems are typically cylindrical in configuration with hollow interiors to permit the flow therethrough of a drilling lubricant that is discharged through the drill bit at the point of drilling. The drill stems are also relatively rigid, and the bore that is being drilled initially extends linearly at an inclined angle that corresponds to the angle of the boom. The angle of attack of the drilling may be altered so that when a desired depth is reached, the drilling operation is changed to progress generally horizontal, or otherwise parallel with the surface of the ground. When the underground bore has reached its desired length, the drill bit can be directed to be angled upwardly until the drill bit re-emerges at the ground surface. This point of emergence then forms the opposite end of the drilled bore hole or tunnel.
Many conventional directional boring machines include an electronic transmitter in the drill bit that aids in tracking both the depth and the ground-relative position of the drill bit After the drill bit reemerges at the ground surface, a reamer is typically attached to the drill bit which is retracted axially backwardly through the borehole, thus reaming out the borehole to achieve a larger diameter borehole. A utility line is commonly attached to the reamer prior to pulling the drill stem and drill bit back through the borehole so that the utility line or conduit is retracted back through the borehole along with the reamer.
Due in part to the minimal impact that directional boring machines have on the surrounding environment, directional boring machines have largely replaced other industrial trenching machines (such as back-hoes and power shovels) for laying utility lines, and have reduced the need for such industrial trenching machines. Despite the reduced need for these other trenching machines, many contractors already have amassed a sizable fleet of such equipment. Due to the current preference for new directional boring machines, these open trench-type trenching machines sit idle for a significant percentage of time, thus being significantly under-utilized. Moreover, despite these old style trench-type trenching machines sitting idle for a significant percentage of time, contractors are unable to completely remove them from their fleets, because they are still useful for performing other types of operations, such as excavating basements of houses and other buildings. Accordingly, there is a need for a method and apparatus that enables contractors to better utilize their fleet of industrial machines
Directional boring machines currently available in the marketplace typically include treads or wheels that are driven by an on-board engine, thus enabling the directional boring machine to be moved and maneuvered under its own power. Furthermore, these directional boring machines typically include on-board power supplies such as hydraulic pumps or alternators that are driven by the on-board engine. The conventional direction boring machines utilize the on-board power supply both to rotate, tilt and axially move the drill stem and drill bit. Unfortunately, the on-board engine, power supplies, and powered treads or wheels cause conventional directional boring machines to be relatively expensive to acquire or lease. Accordingly, many small contractors simply cannot afford to maintain a fleet of conventional directional boring machines, despite the advantages of directional boring techniques over trench
Therefore, a need exists for a directional boring apparatus that is less expensive than conventional directional boring machines.
In accordance with the present invention, a directional boring device is provided for attachment to a carrier having a power source for providing a first power supply to the boring device for moving the device and a second power supply for operating the device. The boring device comprises an attachment frame, and a selectively attachable first coupler for coupling the attachment frame to the first power supply to permit movement of the device. A drill tool assembly is provided that includes a drill head, a drill stem attachable to the drill head, a drill bit attachable to the drill stem and a drill assembly power transmission. The drill assembly power assembly transmission is capable of moving the drill head and drill stem in a path generally parallel to the plane on which the carrier rests. A selectively attachable second coupler is provided for coupling the second power supply to the drill assembly power transmission for permitting the carrier power source to supply power to the drill assembly power transmission to operate the drill tool assembly.
The present invention addresses the above-identified needs, as well as others, with a directional boring apparatus suitable for being used as an attachment with various new or existing types of carrier bodies such as hydraulic excavators, track-type tractors/dozers, standard wheel loaders, articulating wheel loaders, skid loaders, backhoe loaders, agricultural-type tractors, powered industrial trucks, forklifts, trenching machines, trucks, road graders, and roller compactors. Typical carrier bodies include power units such as steering mechanisms, track assemblies, wheel assemblies, internal combustion engines, transmissions, hydraulic systems, hydraulic pumps, electrical systems, batteries, and alternators.
By configuring the directional boring apparatus as an attachment that utilizes power supplied by separate powered carrier bodies, the directional boring attachment of the present invention eliminates a large percentage of the components contained in existing self-contained directional boring apparatus and thereby eliminates a large percentage of the cost associated with implementing directional boring technology. Due to the lower cost of implementation, the directional boring attachment of the present invention provides many contractors with access to directional boring technology that would otherwise be too expensive for such contractors to afford. Further, by implementing the directional boring apparatus as an attachment, the present invention provides contractors with a mechanism by which they can better utilize equipment such as open trench-type trenching machines that would otherwise go idle.
One feature of the present invention is that it has the capability of providing a new method and apparatus for drilling underground bores, which reduces the capital investment required, when compared to known, self-contoured direction boring equipment.
Additionally, the present invention has the advantage of enabling existing carrier bodies to achieve directional boring capabilities.
The above and other objects, features, and advantages of the present invention will become apparent to those skilled in the art from the following description and the attached drawings.